The invention is related to a centrifugal rpm governor for fuel injected internal combustion engines, especially an idling and final rpm governor for Diesel vehicle engines and revealed herein and finally claimed. A centrifugal rpm governor of this design is already known (German Auslegeschrift 22 24 755), in whch the idling spring embodied as a leaf spring is secured on a force transmitting lever which is acted upon by the main control spring and the restoring force of this idling spring is reinforced over a portion of the idling sleeve path by an additional idling spring acting at least indirectly on the control member and also supported on the force transmitting lever. This control spring combination serves to stabilize the idling of the engine, whereby the idling spring is so designed that a sufficiently large load acceptance is possible. Further, the additional idling spring acts in a known manner by partially increasing the P-factor of the "sudden zero-gas stabilization means", by means of which the engine does not stall even on a sudden decrease in load. As a result of the disposition of both springs which affect idling on the force transmitting lever, the exertion of their force is automatically excluded after the idling sleeve path has been covered, so that in an advantageous manner these springs do not affect the characteristic curve for deregulation. When the engine is starting with the service lever in the full-load position, the increased P-factor and the force of the springs which are effective during idling control are also exerted on the deregulation of the increased starting quantity in a disadvantageous way, and the deregulation point of the increased starting quantity moves in the direction of higher rpm. As a result there is a danger that when the engine is heavily loaded and the engine speed is therefore dropping, the maximal fuel quantity defined by the full-load stop is suddenly increased, at appropriately low engine speed, in the direction of the increased starting quantity. As a result, there is a puff of exhaust smoke, and the emission values are impermissibly increased.
From German Patent No. 838,380, an idling and final rpm governor is known whose main control spring is disposed in the flyweights and whose idling spring is disposed in a spring capsule on the governor housing. In this governor, the idling spring is made ineffective when the service lever is at full-load, so that it does not affect the P-factor during deregulation, while a high P-factor is still attained in the idling position of the service lever. This design of an idling and final rpm governor, which diverges from the generic centrifugal rpm governor, does not enable an increased starting quantity which is automatically set in the full-load position of the service lever and controlled by the idling spring, and the effect of the idling spring is not supplemented by an additional idling spring, which has the disadvantage that when the P-factor of the idling spring is sufficiently high there is good sudden zero-gas stabilization but a very poor load acceptance, or when the P-factor of the idling spring is low, there is a good load acceptance but a poor sudden zero-gas stabilization.
In centrifugal rpm governors having--in contrast to the known governors described above--a main control spring pivotable by means of the service lever in order to set the desired rpm and also acting as the idling control spring, it is now known (German Patent No. 2,048,635) to make an additional idling spring supported in the govenor housing at least partially ineffective in accordance with the position of the service lever. In this governor, it is intended thus to preclude any influence by the additional idling control spring on the P-factor of the main control spring during the regulation of the final rpm, because there, especially when used in supercharged Diesel engines, the additional idling control spring leads to an impermissible elevation of the upper zero-load rpm limit. However, this spring exerts no influence on the control of the increased starting quantity.